We report the enhancement in electrocatalytic activity of Mn-O-Co composite electrode developed through chemical reduction method. The Mn-O-Co composite electrode exhibits high catalytic activity with a low Tafel slope of 123 mV dec(-1) and a low overpotential of 117 mV at a current density of 10 mA cm(-2). The enhancement in electrocatalytic activity of Mn-O-Co composite electrode is due to the synergistic activity of MnO and CoO with the NiP matrix. The intermetallic interaction among the half-filled orbitals of manganese with the fully occupied orbitals of cobalt and nickel leads to an effective electron delocalization in the catalytic system which enhances the HER performance of the coating. The C-dl value of the composite electrode is in the order of 254 mu F, which is approximately ten fold higher than the bare NiP coating, due to the enhancement in interaction between the Mn-O-Co composite electrode and the reactive species in the HER medium. The Mn-O-Co composite electrode shows promising characteristics as an electrocatalyst with long term stability and remarkable competency with the commercially available electrodes. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.